s390/zcrypt: ap bus rescan problem when toggle crypto adapters on/off
The bus rescan process was called simultaneously on
every device failure. This finally leads into race
conditions (double device add/remove actions).
This patch protects the rescan area by mutual exclusion
and improves ap_config_timer handling
Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index b8b340a..9de41aa 100644
--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -954,15 +954,11 @@
void ap_bus_force_rescan(void)
{
- /* Delete the AP bus rescan timer. */
- del_timer(&ap_config_timer);
-
- /* processing a synchonuous bus rescan */
- ap_scan_bus(NULL);
-
- /* Setup the AP bus rescan timer again. */
- ap_config_timer.expires = jiffies + ap_config_time * HZ;
- add_timer(&ap_config_timer);
+ /* reconfigure the AP bus rescan timer. */
+ mod_timer(&ap_config_timer, jiffies + ap_config_time * HZ);
+ /* processing a asynchronous bus rescan */
+ queue_work(ap_work_queue, &ap_config_work);
+ flush_work(&ap_config_work);
}
EXPORT_SYMBOL(ap_bus_force_rescan);
@@ -1305,8 +1301,9 @@
int rc, i;
ap_query_configuration();
- if (ap_select_domain() != 0)
+ if (ap_select_domain() != 0) {
return;
+ }
for (i = 0; i < AP_DEVICES; i++) {
qid = AP_MKQID(i, ap_domain_index);
dev = bus_find_device(&ap_bus_type, NULL,